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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
1
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pubmed:dateCreated |
1984-9-12
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pubmed:abstractText |
The energetics of alpha-aminoisobutyric acid transport were examined in Vibrio costicola grown in a medium containing the NaCl content (1 M) optimal for growth. Respiration rate, the membrane potential (delta psi) and alpha-aminoisobutyric acid transport had similar pH profiles, with optima at 8.5-9.0. Cells specifically required Na+ ions to transport alpha-aminoisobutyric acid and to maintain the highest delta psi (150-160 mV). Sodium was not required to sustain high rates of O2-uptake. Delta psi (and alpha-aminoisobutyric acid transport) recovered fully upon addition of Na+ to Na+-deficient cells, showing that Na+ is required in formation or maintenance of the transmembrane gradients of ions. Inhibitions by protonophores, monensin, nigericin and respiratory inhibitors revealed a close correlation between the magnitudes of delta psi and alpha-aminoisobutyric acid transport. Also, dissipation of delta psi with triphenylmethylphosphonium cation abolished alpha-aminoisobutyric acid transport without affecting respiration greatly. On the other hand, alcohols which stimulated respiration showed corresponding increases in alpha-aminoisobutyric acid transport, without affecting delta psi. Similarly, N,N'-dicyclohexylcarbodiimide (10 microM) stimulated respiration and alpha-aminoisobutyric acid transport and did ot affect delta psi, but caused a dramatic decline in intracellular ATP content. From these, and results obtained with artificially established energy sources (delta psi and Na+ chemical potential), we conclude that delta psi is obligatory for alpha-aminoisobutyric acid transport, and that for maximum rates of transport an Na+ gradient is also required.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0006-3002
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
27
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pubmed:volume |
766
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
77-87
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pubmed:dateRevised |
2008-11-21
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pubmed:meshHeading |
pubmed-meshheading:6743651-Aminoisobutyric Acids,
pubmed-meshheading:6743651-Biological Transport,
pubmed-meshheading:6743651-Hot Temperature,
pubmed-meshheading:6743651-Hydrogen-Ion Concentration,
pubmed-meshheading:6743651-Kinetics,
pubmed-meshheading:6743651-Oxygen Consumption,
pubmed-meshheading:6743651-Sodium,
pubmed-meshheading:6743651-Vibrio
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pubmed:year |
1984
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pubmed:articleTitle |
Energetics of sodium-dependent alpha-aminoisobutyric acid transport in the moderate halophile Vibrio costicola.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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